The data on the page seems a bit... iffy. Apparently only 3 languages have "Ifs", and 7 languages have for loops.
The "coverage" for all 388 columns is listed on the CSV page.
For example, you can see the coverage for "forLoops" is 0%: https://pldb.io/csv.html#q=forLoops&order=2.asc
Resources and time is limited.
I would LOVE any grants/donations to prioritize coverage on any column that people are interested in.
Otherwise, data get added by volunteers.